Why do I have a call log for 3 days only?

Hi everyone,
After the update to 10.3.1 all call logs which earlier used to Remain for 30 Days is now for 3 days only.... is their a way to correct it or its a common issue...?

BlackBerry company knows about the problem? Any way to inform them.

Moreover how to get a dark screen while calling as it was in 10.2.1 as white screen looks more like a phone and, dark screen is the plus point of BlackBerry.... is there any options to convert it to dark.